Air-cooling of glass bulb rectifiers



June 18, 1935. F. GEYER 2,005,031

AIR COOLING OF GLASS BULB RECTIFIERS Filed May 14, 1930 5 Sheets-Sheet 1 June 18, 1935.

GEYER AIR COOLING OF GLASS BULB RECTIFIERS Filed May 14, 1930 5 Sheets-Sheet- 2 June 18, 1935. F GEYER 2,005,031

AIR COOLING OF GLASS BULB RECTIFIERS Filed May 14, 1930 5 Sheets-Sheet 3 June 18, 1935. F. GEYER 2,005,031

AIR COOLING OF GLASS BULB RECTIFIERS Filed May 14, 1950 5 Sheets-Sheet 4 June 18, 1935. u F. GEYER I 0 1 AIR COOLING 0F GLASS BULB RECTIFIERS Filed May 14, 19 30 5 Sheets-Sheet 5 Patented June 18, 1935 PATENT OFFICE Am-cooLINe "or GLASS BECTIFIERS I Geyer, Vienna, Austria, assiznorto Elia Aktitmsesellschaft. fiir: elektrische Industrie,

Yienna s-Austria Application May 14, 1930,

Serial No. 452,496

In Austria {August as, 1929 13 Claims; (o ese-27,5;

- This invention relates to a new and improved cooling system for the containers ofglass b ulb rectifiers. In the arrangement generally followed the Ian producing the fcool'ing'current of air is situated below" the bulb andblows a stream of air upwards on to the cathode, past the arms, and finally towards the cooling head. 'Ifhisarrangement is dictated by the f consideration, strictlycorrectfrom aphysical point'of view, that the resistance to the movement of the cooling air is slightest and the heated air can be most rapidly disposed of without dangerof its re"- turning to the container to be cooled ii the stream of cooling air is-directed upwards,follow'ing' the natural-tendency of'heated air to rise. The anode arms, however, impede theeven fiow'of the air and give rise to the formationof eddiesyso that cylindrical orconical guide sheets arefrequently employed in the attempt to obtain. adequate draught over the surface; of the cooling head, If the distribution of the temperature of. a glass bulb cooled in the manner indicated is examined it will be foundthatprecisely that 'portionwhi'cjh should be maintained coolest; namely the cooling head, is swept by a'current orair-whicnhas become heated by contactwith the "hottest parts of the bulb, the anode arms. 'But even iithe' quantity of the cooling air employed "beincreased to such an extent that the air in traversing the region of the bulb does-not 'becomeapprecia-bl y heated, this arrangement nevertheless has the-further drawback that the crown of;

the cooling head remains -outof' reach of the cooling current' 'and is rendered "valuelessi for cooling purposes.

In accordancewith the presentinvention the" above-mentioned drawbacks are avoided by ,the. provision of a cooling systenr in which'the' cure n rent of-coolingair is blown'downwards' from above on to theglasscontainer, so'that'the fresh aircurrent is caused to meet first the coolest portion of the'bulb, namely the-cooling head fThie warmed air drivenjd'ownwards has naturally the tendency to rise again by the shortestroute and to mix with; thiegfresh" cooling. air, which would result a very considerable reduction of. the .cooling effect. This tendency lcanfbefc ounter acted by the suitable erection of the rectifying cell or by the suitab1eshapingo the chamber or 5m in. which the. sameisl lmounted, Even; then, howevea'gtheflow of the cooling currentis: apt tabs irregular consequence of the presenceoi the anode arms. Animprovement this respect can. beobtained, by the. 111G111!- form of construction the current of air is deflectsion of various auxiliary means, as shownin t e accompanying drawings, in which: I I I 5 Fig. l-showsin elevation a rectifier with aguide sheet surrounding the cooling head.

Fig. 2 is asimilar elevation of a modified form 5 of construction embodying subsidiary deflecting sheets, I v r r Fig. 3 shows'in elevation a rectifier with a cylindrical cooling head and appropriate air guiding sheets. I Figs.4 to 6 illustrate'specially formed guiding and deflecting sheets for use in connection with bulbs having-cylindrical cooling heads with re entrant cooling surf-aces. Figs; land 8 illustrate modifications embody: ing a. bypass" for a portion of the coolingair current; a i

Referring to Fig; 1 an; air' guidingsheet I 4 is interposed between the cooling head- I and the anode arms 2, so that a current of air generated for instance by a fan '1;- and directed downwards from above divided-into twoparallel streams,

ofWhichthe inner stream is capable of carrying the greater quantity of'airand-plays over the whole length of the main body of the bulb I' together with the inner portion of the lower arms 2' and the cathode 3; while the outer stream sweeps pastthe anode arms 2 and the remaining portion of the lower arms 2'. a

'asin'ce however'experience has shownthat an intensive cooling of the: anode arms 2 is'notalways desirable it has proved preferable, under certain circumstances; to provide the arrangement of guide sheets show-n Fig. 21' In this edibelow the 'cathodeby meansof a second sheet 5, which diverts the stream of air either partially or entirely along the anodearms in an upward direction, so that the anode arms 2' are only swept by preheated air and'are' protected from becoming cooled: to too great anextent. The required draught of air can either be generated by aifanv situated immediately above the bulb; as-indicated in Figs. 1 and 2, or'c'an be generated by'a fan or blast mounted independently of the rectifier, conductedto the latter by means-of a pipeline, and finally caused to impinge: on the bulb from above.

: It has-proved advisable inthe case of highcapacity glass bulb rectifie'rs to depart from the" hitherto usual pear shape of bulb, and-to adopt a slender shape, which could be strictly cylindrical except for considerations of strength; for the cool-' ing-head. This form" makespossible the provision of "exact; air guidance with comparatively slight-current cross-section, which leads neces-' sarily 'to an -increase in the rate of flow of the I cooling air, and-at the same time to a considerable intensification of the cooling effect.

Fig. 3 shows diagrammatically an arrangement of this type, wherein l denotes the glass bulb, 4" the guiding sheet disposed parallel to the cooling space proper, and 5 the sheet which deflects the current of air partly to. serve forthe coolingj'of the arms 2, and partly for cooling the lower'part of the bulb below the cathode 3. v

In some rectifiers the cooling head is providedwith a reentrant portion; to ,1ncreas e its cooling effect. The system of guide sheets re uired for cooling such a bulb in accordancewith myinven-q tion is shown diagrammatically in Fig. 4, in which the guide sheets are represented by 4, 5, and 6; the course taken by the coolingairbeing-clearly indicated by the arrows. Here again theconnten, current principle (the cooling air travelling inthe opposite direction to the mercury vapour) isrig= idly adhered toforthe coolingof the-cooling space proper. g The exact air spaces surrounding the cooling chambers proper 0 n.i h a t-men io d ne; (it-bulb, and requires, as already mentioned, high rates of flow of the cooling air in order. that adequate quantities thereof can beforced through the narrow air channel cross-sections. It is not always possible to develop the pressure required for this purpose by means of fans, so that it is frequently necessary to employ blowerswith pressures up to 200 mm. about 8 ins.) water column for the generation of the air current, ,It is however by no means necessary toprovide a blower dimensioned for the same quantity of air as would be required if the draught were generated by means of aian. The cooling effect of the air is far more favourable with high rates of flow, andiunder these conditions the cooling air is almost perfectly exploited, that is to say leaves the region of theflbulb at a uniform temperature, while; the air blown past the bulbs by fans isvery irregularly heated; so that only asmall proportion thereof can be regarded as effective for cooling purposes.

This exact air guidance by means oficlosed guiding sheets with the .morefavourable efiect obtainable by means of aregulated current at .a high rate of flow can only be realized with Sim--v -ple means in the case of .the bulbs, of a slender shape, and then only along the actual cooling chamber I, while slowerrates of flow and more Or less unregulated currents occur inthe case of complicatedly shaped. arms 2, insofaryas the latter are not individually cased, in. But since a too extensive casing in of the-glass containeris preferably avoided in view of dimculties'in erecting and dismantling it can become necessary to. me crease the amount of the cooling airdelivered by the blower beyondthat whichis necessary for. the cooling head proper in order-to obtain an adequate current along the -2iandt'thexlowerportion 3 of the bulb. The deliveryof large quantities of air at high pressure has,however, a detrie mental effect on the efliciencyof the plant, on account of the considerable consumptionof power required therefor. Itis :thus more advisable to conductto the coolinghead Ifonlythe actual quantity of air required, and to use the-speedbf this primary air current at theexit'from the an-. nular space 4 (Fig. 5) inconjunction with a further sleeve 1 to obtain aninjector-like effect capable of setting up a subsidiary; currentade-v quate for the suitable cooling of the arms and of r the lower rtionpi the b m. By. this meansithe consumption of energy can be kept down to a minimum. Air under pressure is supplied to the upper end of'casing 4' by blower IS.

The arrangement as shown in Fig. 5 complies with the various requirements enumerated and takes account of the temperatures in the cooling chamber I and at the anode arms 2, providing forthe former a smaller'quantityf of air with a vigorous blowing effect at a high rate of flow, and for the latter a larger quantity of air at a lower rate of flow. A similar result can be achieved by the combined use of a blower and of a fan 01'. This arrangement is shown in Fig.

6. The cooling head proper. I is again equipped 15.; At 4 the blower draft mixes with the stream of air generated from below by the fan in, for which latter. stream a guiding sheet 5' is likewise provided, which ensuresthe proper cooling of both the cathode portion; of the bulb and the anode arms 2. i i

The efiectachieved by the use of an auxiliary fan can also be achieved by an arrangement as shown in'Fig. 7, in which-a portion of'theair blown against the cooling head is diverted by meansfof a branch pipe 8, conducted through a by-pass 9 and blown through an opening. .10 against. the cathode portion of the bulb. This arrangement has the advantage or being con-,

siderably simpler in construction than that em ploying a separate fan (in inFig'.'6). y l v Fig. 8 villustrates the employment of theabove described principle in connection with a rectifier bulb having a re-entrant cooling extension 6. with the. air "guiding tube I 6' pertaining thereto in an arrangement in whichthe downwardly directed air current is divided into lthrfifl pore tions of which theone is blown directly on to and past the cooling head, while the second is directed" by means of the tube 9 ;agai nst the cathode, and'the third is directed into thecool ing extension 6 whence this portion oftheair current is discharged into the outer air through the bent tube 6. This arrangement developsa particularly advantageous cooling effect 7 v I claim:- j l '1 In combination with a glassbulb rectifier having a cooling head, anode arms, and a cath-e ode, means for generating a currentjof air,; and means for directing said current of -jair against. the top of said cooling; head and,; causing,said current to now along the entire outer surface of said co'olinghead and across said anode arms in the direction of said cathode r 2 In' combination with a: lass bulb having a cooling head, anode .arms extending laterally with. respect to said cooling head. and a cathode, means for generating a current 0f cooling "air, and means for directing said ,cur-

for the cathode portion rent against the top ofg saidlcooling head and causing said, currentflto outer surface of said cooling headand said anode arms in the directionjofs'aid cathode, said meanscomprising guide surfaces,@surroiii ad ing said cooling head and'looated gflowaiorie the, t me generating a current of air and directing the same against the upper end of said cooling head, said first mentioned guide sheet being adapted to guide the current of air along said cooling head,

having anodes, a cathode, and a substantially cylindrical cooling head, substantially cylindri-' cal guide means surrounding said coolinghead and forming a narrow passage around the same, and means for maintaining a supply of air under pressure in the end of said guide means furthest from said cathode. v

5. In combination with a glass bulb rectifier having a substantially cylindrical cooling head, anode arms extending laterally with respectto said cooling head, and a cathode, a substantially cylindrical guide sheet surrounding said cooling head in spaced relation thereto and forming a narrow passage around the same, a guide sheet below said anode arms, and means for maintaining a supply of air under pressure in the end of said first mentioned guide sheet furthest from said cathode, said second mentioned guide sheet being adapted to deflect air issuing from the adjacent end of said first mentioned guide sheet outwardly along said anode arms.

6. The combination with a device as specified in claim 4, of a sleeve surrounding the end, of said guide means nearest said cathode and spaced therefrom in such relation as to produce an injector effect on the air in the vicinity of the bulb.

7. The combination with a device as specified in claim 4, of a sleeve surrounding the end of said guide means nearest said cathode and spaced therefrom in such relation as to produce an injector eifect on the air in the vicinity of the bulb, and a guide sheet below said anode arms adapted to deflect the airoutwardly along said arms.

8. In combination with a glass bulb rectifier having a cooling head, anode arms extending laterally with respect to said cooling head, and a cathode, a guide sheet surrounding said cooling head in spaced relation thereto and between the latter and said anode arms, means for generating a current of air and directing the same against the top of said cooling head, whereby said current is caused to flow along said cooling head in the direction of said cathode, and an auxiliary fan adapted to generate an additional stream of cooling air impinging against said cathode and flowing toward said anode arms.

9. In combination with a glass bulb rectifier having anodes, a cathode, anda substantially cylindrical cooling head, substantially cylindrical guide means surrounding said cooling head and forming a narrow passage around the same, means for maintaining a supply of air under pressure in the end of said guide means furthest from said cathode, and an auxiliary fan adapt ed to blow additional cooling air against the cathode of said rectifier and toward said anode arms.

10. In combination with a glass bulb rectifier having a cooling head, tending laterally with respect to said cooling head, and a cathode, a guide sheet surrounding said cooling head in spaced relation thereto and between the latter and said anode arms, means for generating a current of air within said guide sheet directed against the upper end of said cooling head and flowing along said cooling head toward said cathode, and means for by-passing a portion of said air current from above said cooling head and directing the same I against said cathode in a direction opposed to the main current of air. I

11. In combination with a glass bulb rectifier having a cathode, anodes, and a cooling head provided with a re-entrant cooling surface, guide means surrounding said cooling head, means for blowing a current of air within said guide means toward the re-entrant portion of said cooling head, and a tube leading from the exterior of said guide means into said re-entrant portion and terminating near the inner end thereof.

12. In combination with a glass bulb rectifier having a cathode, anodes, and a cooling headprovided with a re-entrant cooling surface, means forming a casing surrounding said cooling head in spaced relation thereto, means for supplying air under pressure to the end of said casing remote from said cathode, and a tube leading from the exterior of said casing 'into said re-entrant cooling portion and terminating near the inner end thereof.

anode arms ex- FRANZ GEYER. 

